The present invention generally relates to sockets for integrated circuit (IC) devices, and, more particularly, to the construction of covers for IC sockets which hold IC chips in electrical contact with the pin array of the socket.
Sockets for holding IC chip packages are widely known and used in a variety of industrial applications for achieving efficient electrical contact between the I/O contact array of an IC device and the conductor pads of a circuit board. Such applications include test sockets for mounting a device under test (DUT) to a test board and contactor sockets for removably mounting an IC device to a printed circuit board. The socket functions to precisely position the IC device over the pin array of a test or contactor socket, such that all of the I/O contacts of the device make efficient electrical contact with the socket's pin array.
Socket covers have been devised for depressing the IC chip package in the socket and against the socket's pin array in a controlled z-axis movement. One such cover is disclosed in U.S. Pat. No. 6,354,859, wherein the cover for the IC socket includes a lid that closes over the top of the socket and a threaded depressor element in the center of the lid. When placed over the socket, the lid's depressor element is advanced by screwing it down in the z-axis direction against an IC chip package so as to press against the top of the package. The difficulty with such prior socket cover designs is that the threaded depressor construction is relatively rigid and bulky, and involves frictional forces that impair the ability of the depressor to provide a precise and uniform actuating force. The bulky lid and depressor construction also limits the ability of the socket cover to carry away heat generated within the IC chip.
A need therefore exists for an IC socket cover design capable of producing and maintaining precise actuating forces on an IC chip package and capable of efficiently dissipating heat produced by the chip.